Yacht Measurement Abbreviations

The following yacht measurement abbreviations are often used to describe various measurements on a sailboat: Rig Dimensions, Fore Sail Dimensions (including Spinnaker Dimensions) and Main Sail Dimensions. Technical definitions exist for most of these abbreviations and the various handicapping organizations have specific measuring standards,  but the following is a list of simple descriptions with links to simple illustrations.

Other Abbreviations Lists: Sail/Yacht Racing National Sailing Federations Consolidated List
Acronym/ AbbreviationWhat does it mean
ALE"Spinnaker Leech":- (Asymmetrical) Measured from head to foot.View Illustration
ALU"Spinnaker Luff ":- (Asymmetrical) Measured from head to foot.View Illustration
AMG"Asymmetric Mid Width":- (Asymmetrical) Distance between the mid points of the luff and leech.View Illustration
ASF"Asymmetric Foot Length":- (Asymmetrical) The shortest path on the surface of the sail connecting the tack and clew.View Illustration
BAS"Mast Datum Point":- The vertical distance between the sheerlane at the mast and the top of the boom (or lower black band).View Illustration
BWL"Beam of Waterline":- Width of the beam at Waterline.
DWL"Design Waterline":- The Designed length of the waterline.
E"Mainsail Foot":- Horizontal distance measured from aft face of mast at top of boom to boom band or maximum outhaul position.View Illustration
Ey"Mizzen Mainsail Foot":- Horizontal distance measured from aft face of mizzen mast at top of boom to boom band or maximum outhaul position.View Illustration
FHB"Flying headsail Headboard":- Top width of the sail.View Illustration
FHW"Flying headsail Half Width":- 1/2 of the way up the leechView Illustration
FL"Forestay Length".
FLP"Flying headsail Luff Perpendicular":- Shortest length from clew to luffView Illustration
FLU"Flying headsail Luff Length":- From tack to headView Illustration
FQW"Headsal Quarter Width":- 1/4 way up the leechView Illustration
FSA"Flying headsail Area".View Illustration
FSFL"Flying headsail Foot Length".View Illustration
FTW"Flying headsail Three Quarter Width":- 3/4 of the way up the leechView Illustration
FUW"Flying headsail Upper Width":- 7/8 of the way up the leech.View Illustration
HHB"Headsail Headboard":- Top width of the sail.View Illustration
HHW"Headsail Half Width":- 1/2 of the way up the leechView Illustration
HLP"Headsail Luff Perpendicular":- Shortest length from clew to luffView Illustration
HLU"Headsail Luff Length":- From tack to headView Illustration
HQW"Headsal Quarter Width":- 1/4 way up the leechView Illustration
HSA"Head Sail Area".
HTW"Headsail Three Quarter Width":- 3/4 of the way up the leechView Illustration
HUW"Headsail Upper Width":- 7/8 of the way up the leech.View Illustration
I"Height of Foretriangle":- Elevation of Forestay, measured down to Mast datum point (see BAS).View Illustration
Is"Height of Inner Foretriangle":- Elevation of Forestay, measured down to Mast datum point (see BAS).View Illustration
ISP"Elevation of Spinnaker Halyard":- Measured down to Mast datum point (see BAS).View Illustration
J"Base of Foretriangle":- Horizontal distance measured from front face of mast at deck to position of headstay at sheer line.View Illustration
Js"Base of Inner Foretriangle":- Horizontal distance measured from front face of mast at deck to position of inner headstay at sheer line.View Illustration
LOA"Length Overall":- Overall length of boat normally not including appendages.
LOD"Length of Deck":- Length from Bow point to the intersection of the deck and transom.
LP"Headsail Luff Perpendicular":- Shortest length from clew to luffView Illustration
LWL"Load Waterline":- The actual waterlin lenghth with load (Normally DWL).
LWL"Length of Waterline".
MHB"Main Head Board":- Width of the Main's Headboard.View Illustration
MHW"Mainsail Half Width":- 1/2 of the way up the leech.View Illustration
MLB"Maximum Batten Length".
MQW"Mainsail Quarter Width":- 1/2 of the way up the leech.View Illustration
MTW"Mainsail Three quarter Width":- 3/4 of the way up the leech.View Illustration
MUW"Mainsail Upper Width":- 7/8 of the way up the leech.View Illustration
P"Mainsail Hoist":- Elevation of upper mast band or maximum main halyard position, measured down to lower mast band or top of boom.View Illustration
Py"Mizzen Mainsail Hoist":- Elevation of upper mast band or maximum main halyard position, measured down to lower mast band or top of boom.View Illustration
QCD"Quadrilateral main Clew Diagonal":- Measured from the thtroat to theclew.View Illustration
QFL"Quadrilateral main Foot Length":- Measured from the Peak to the ClewView Illustration
QHL"Quadrilateral main Head Length"View Illustration
QLE"Quadrilateral main Leech Length":- Measured from the Peak to the ClewView Illustration
QLM"Quadrilateral main Width":- Measured from the throat to the half leech point.View Illustration
SA"Sail Area".
SF"Spinnaker Foot":- (Symmetrical)The shortest path on the surface of the sail connecting the tack and clew.View Illustration
SFL"Spinnaker Foot Length":- The shortest path on the surface of the sail connecting the tack and clew.View Illustration
SHW"Spinnaker Half Width":- Measured by determining the mid points of the luff and leech and the width is the shortest path connecting those two points.View Illustration
SL"Spinnaker Luff ":- (Symmetrical) Is measured along the edges of the sail from the head to the footView Illustration
SLE"Spinnaker Leech Length".View Illustration
SLU"Spinnaker Luff Length".View Illustration
SMW"Spinnaker Maximum Width":- (Symmetrical) Equidistant from the head. For most spinnakers the maximum width will be near the center of the sail, but it may also be across the foot.View Illustration
SPA"Spinnaker Area"
SPL"Spinnaker Pole Length":- View Illustration
STL"Spinnaker Tack Length":- Horizontal distance measured from front face of mast at deck, forward and horizontally to position of spinnaker tack attachment point.View Illustration
TPS"Tack Point of Spinnaker":- Horizontal distance from the face of the mast to the point of attachment at deck level for deck tacked spinnakers or the extreme forward end of any bowsprit when fully extended for sprit tacked spinnakers.View Illustration

The above list of Yacht Measurement abbreviations have simple descriptions and the linked illustrations are only a simple representation of the abbreviation and how that abbreviation relates to the component the subject component.

Very specific specifications exist for most of these yacht measurements abbreviations, how they are measured, how datum points are determined and how these datum points are utilised, this information is not reflected in the above descriptions or the illustrations that they link to.

Further information on rating measurements can be found at various rating organizations including:
Offshore Racing Congress (ORC) 
International Rating Congress (IRC)
Classic Rating Formula (CRF)

Simple illustrations for these sail and rig measurement abbreviations can be found:

Fore Sail Dimensions Main Sail Dimensions Rig Dimensions
Yacht Measurement Abbreviations - Fore Sail Dimensions Yacht Measurement Abbreviations - Main Sail Dimensions Yacht Measurement Abbreviations - Rig Dimensions